Locking device

ABSTRACT

The locking device is used with plug-in members, such as electric plug connections. A threaded spindle is swingable from a frame which supports the plug-in members. A control grip and an internally threaded member move back and forth on the spindle depending on their direction of rotation on the spindle. A tapered ring on the spindle is engageable with a hook on one of the plug in members. When the control grip is tightened the ring presses the hooked member into insertion. When the control grip is loosened the ring can be released from the hook. The control grip is coupled to the internally threaded member by Hirth type serrations, spring loaded by a donut shaped spring cushion which allows the control grip to be displaced from the internally threaded member when a predetermined plug-in force is exceeded.

ilnited States Patent 1191 4/1971 MacMaster et a1. 339/75 M Weber Mar. 12, 1974 LOCKING DEVICE Primary Examiner-JOSeph H. McGlynn [76] Inventor: Erwin Weber, Flurstrasse 18, 8034 v Unterpfaffenhofen, Germany 221 F1 d M 13 1972 [57] ABSTRACT ar. y l e The locking device is used with plug-in members, such PP 234,150 as electric plug connections. A threaded spindle is swingable from a frame which supports the plug-in 30 F n A P D members. A control grip and an internally threaded 1 D g [on n n y member move back and forthon the spindle dependec. 1 1 ennany 2162/92 I ing on their direction of rotation on the spindle. A tag pered ring on the spindle is engageable with a hook on [52] US. Cl. 33931563122323 one of the vqy q when the control grip is Cltightened, the presses the hooked member into [58] Flew 9 Search 3 g insertion. When the control grip is loosened the ring I can be released from the hook. The controlgrip coupled to the internally threaded member by Hirth [56] References cued type serrations, spring loaded by a donut shaped UNITED STATES PATENTS spring cushion which allows the control grip to be dis- 3,l57,450 11/1964 Harrison, Sr. et al 339/91 R placed from the internally threaded member when a 3,569,910 3/1971 Poe 339/91 R predetermined plug-in force is exceeded 3,575,482

3 Claims, 6 Drawing Figures The invention relates to a locking device for a connection between inserted members, especially electric plug connections, and a mounting device that can be used with such inserted members, this mounting device having a pair of matched members, with an axis of rotation located on the frame, with a spindle whose one end is rotatable around the axis of rotation, with a hook, pointing forward, at the point of insertion, with a control grip on the spindle, moving back and forth on the spindle, in dependence on the direction of rotation, and with a tapered ring that is positioned coaxial with its inner diameter around the threaded spindle, which has an inner taper opening toward the axis of rotation, which can be made to engage with the hook, which can be pressed onto the hook by rotating the control grip in the direction for tightening and can be released from the hook by rotating the control grip in the direction for loosening, provided the control grip is loosened sufficiently, the control grip being form-locked and force-- locked to an inner thread of the spindle by means of a locking joint, capable of locking on in one direction when pushed in with a certain amount of force and held under tension by a spring device.

In the device relating to the main application, the unidirectional locking joint requires the use of a larger. number of parts. Since the entire locking device is rather small, having for example a maximum outer diameter of 26 mm, the parts of the locking joint must themselves be kept small. If it is assumed that the locking on takes place when the inserting force is on the order of 50-150 kp and the forces required for loosening the device are on the same order, then it is easy to see that the only parts capable'of sustaining such stresses are those made of veryhigh quality materials and subject to narrow toleration limits.

The object of the invention is to provide a locking joint made of substantially less parts while substantially improved in its capability of withstanding the stresses that arise, and which in particular possesses a lower compressive stress per unit area.

This object is achieved in terms of the invention by the fact that the control grip and the inner thread possess I-Iirth-type serrations on their opposing surfaces.

Further advantages and characteristics of the invention can be learned from the following description of a preferred form of embodiment. The drawings show the following:

FIG. 1 shows a longitudinal section of the device in its locked position.

FIG. 2. shows an unsectioned view corresponding to FIG. 1, but shortly after the inserted element has become slightly loosened but not completely disengaged.

FIG. 3 shows a front view of the catch.

FIG. 4 shows a longitudinal section of the interior of the threaded portion.

FIG. 5 shows a view corresponding to that of the arrow A in FIG. 4.

FIG. 6 shows an enlarged view from the standpoint indicated by the arrow B of FIG. 4, projected onto a flat surface.

A frame 31 is anchored to a particular spot and has a pair of plug-in elements in its rear area. An eye 33 with a transverse hole 34 is provided beneath the bottom 32 of the frame and in front of it.

The front of the plug that is to be supported inside the frame 31 grips a frame 36, to which a front panel 37 is fastened. Below and in front of the front panel 37, a hook 38 is rigidly fastened, whose projection 39 runs more or less horizontal and whose lower edge is more or less in line with the lower edge of the front panel 37. The inserted element is capable of sliding over the floor 32, and in its rear area bears the usual plug element that is to be joined to the plug element of the frame 31.

A secure fastening is insured if the plug elements are pressed together with a given amount of force. If the force is insufficient, the plug elements will not properly unite, and if the force applied is too great, then damage will result.

A cross pin 41 becomes seated in the transverse hole 34, this pin also lying in a direction transverse to a square socket 42 of a threaded bolt 43. Thus the threaded bolt 43 is capable of rotating around the longitudinal axis of the cross pin 41, but cannot turn around its own longitudinal axis. The right half 44 of the threaded bolt 43 is smooth, while its left half has a a thread 46 that cannot be reached from outside, due to-the presence of a locking washer 47. Theunderside of the right portion 44 bears a traction groove 48, which stops just short of the thread 46. A jacket 49 has an inner diameter slightly larger that the outer diameter of the threaded bolt 43, so that it can be pushed back and forth along it. At its left end it possesses an outer flange 51, which defines a front surface 52 on the left and an encircling shoulder on the right. In the area around its lower right end, an inner thread 54, lined up with the traction groove 48, is cut into the wall and is traversed by the shaft of'a screw 56, the free end of which protrudes slightly into the traction groove 48 and.

prevents the jacket 49 from moving too far to the left. The jacket 49 also has a longitudinal guide rail that permits an axial motion but not rotatio A catch plate 57 has the profile shown in the figures. The hole 58 drilled through it matches exactly the right end of the jacket 49. Its inner thread 59 is traversed by the shaft of the screw 56, and the catch plate 57 is in this way fastened securely to the jacket 49. As can be seen from FIG. 1, when the threaded bolt 43 is pulled out, it swings outward to about 8 from the horizontal. Corresponding to this, the catch plate 57 has a flat, linear chamfer 6.1 of 8 along its upper end, so that when the:plug is pulled out the catch plate 57 is allowed to lie flat, with a large contact surface, behind the lower trailing edge of the front panel 37. At the level of the central axis of the hole 58, two guide pins 62 are screwed in on the'right and on the left. These serve to maintain a distancc between a tapered ring 63 and the catch plate 57, since these correspond to the thickness of the front panel 37 and the hook-38. This tapered ring 63 is rotationally symmetrical and has a central hole 64, which is a scant one-tenth of a milimeter larger than the outer diameter of the jacket 49. Since the central hole 64 can have only one particular length, the tapered ring 63 can turn in a helical path around the jacket 49, as long as it is subjected to a load. At such a point the guide pin 62 forms an obstruction.

This protrudes into an opening in the shape of a truncated cone 66, that is of a depth such that it can adequately accommodate the hook projection 39. This is of such a dimension that when it is locked it causes the hook projection 39 to be wedged between itself and the jacket 49. To prevent it from colliding with the hook 38, an outward bevel 67 is likewise provided. On the reverse side of this, the tapered ring 63 reverses its rotational direction, so that an inner face 68, an encircling shoulder 69 and a face 71 occur in the form of a ring-shaped profile.

A spacer ring 72 is rotationally symmetric in form, and its center hole 73 is capable of moving axially or of rotating on the jacket 49. Its cross section is that of the letter Z. The right front face 74 of its inner flank is of the same size as the inner face 68 of the tapered ring 63. The left face 76 is capable of making contact with the outer flange 51 of the jacket 49. The encircling shoulder 77 corresponds in its diameter to that of the encircling shoulder 69. Both of these serve to anchor the ends of a helical pressure spring 78. The outer left face 79 serves as a stop for a set of cup springs 81, whose outer diameter is somewhat smaller than the outer diameter of the spacer ring 72 and whose inner diameter allows it to pass freely over the outer flange 51. The outer right face 82 serves as a stop for the inner face 83 of a coaxial compression ring 84. The inner diameter of this ring is larger than the outer diameter of the helical spring 78, so that the helical spring 78 can be moved out of the compression ring 84 under certain operational conditions. The right face of the compression ring 84 is able to make contact with the outer face 71 of the tapered ring 63 at the point when the locking operation is nearly complete.

The compression ring 84 is part of the inner threaded portion 86, shown in detail in FIGS. 4 and 5.

Insofar as the shape of this is not further described, the reader is referred to the figures, which give an accurate representation of the lock on a scale of 2:1. The internally threaded device 86 can be divided for the sake of description into a hubcomponent 87 and a cup component 88. Both the set of cup springs 81 and the spacer ring 72 fit into its circular-cylindrical inner chamber 89. The inner chamber 89 is partially sealed off the outside by the compression ring 84, for the seating of which a recess is provided. The inner surface of the floor 92 forms the other abutment against which the cup springs act, while Hirth-type serrations 93 are provided on the outer surface, extending as far as the hub component 87, whose teeth have a vertical flank 94, about 1 mm high, a small horizontal head 96, and an obligue flank 97. On the inner floor 92 a coaxial recess 98 has been provided, which extends into the hub component 87 and serves partly as a bearing and partly as a guide for a helical spring 99, which is coaxial with the threaded bolt 43 and can be displaced along it.

The helical spring 99 presses against the outer flange 51 and forces the jacket 49 in the direction of the transverse hole 34. The catch plate 57 is thus held clear of the front panel 37. But when the jacket 49 is pulled to the left by loosening the spacer ring 72, then the helical spring 99 is compressed for a short distance, after which 57 encounters the chamfer 61 behind the front panel 37. I

An inner thread 101 is provided for the hub component, which works in conjunction with the thread 46. An outer thread 103 lies to the left of a smooth cylindrical perimeter 102.

A handle 104, which is in other respects rotationally symmetrical, has a central hole 106, whose diameter is larger than the cylinder perimeter 102. Its outer diameter is approximately 26 mm.'A series of Hirth-type serrations 107 are located on its right frontface, these being complimentary to the serrations 93 and working in conjunction with them. To improve the gripping properties of the handle 104, its exterior is knurled. Opening to the left, it possesses a recess 108 with a larger diameter and a recess 109 with a smaller diameter. The latter accommodates a spring cushion 111, which is first knitted with thin metal fibers in the form of a stocking, corrugated, rolled up, and then pressed into the shape shown in the drawing. The left front side of the spring cushion 111 is provided with a washer 1 12. This is interposed between the spring cushion 111 and a nut 113, which is screwed onto the outer thread 103 and is seated inside the recess 108. When the nut 113 is turned further into the recess 108, then the spring cushion 111 is pressed more tightly together, and the latter thus presses the Hirth serrations 107 more tightly against the serrations 93. Since the spring cushion 111 has strongly reproducible properties, it is possible to use this to adjust to the point when the Hirth serrations 93 and 107 will be overlocked. The handle 104, due to its manner of construction, already described, can be displaced to the left when the locking process begins, i.e., when the flanks 97 slide together, one on top of the other. If the flank 94 has a height of 1 mm, then it is possible to adjust this so that the spring cushion 111 exerts a pressure of kp, to give an example.

The device operates as follows: The tapered ring 63 is suspended over the hook projection 39. The outer front face 71 is located at a considerable distance from the compression ring 84, which remains free of tension throughout the length of the helical spring 78. The handle 104 is then turned to the right, which pulls the internally threaded device 86 in the same direction. The interval between the front faces 74 and 68 grows smaller and smaller until they come in contact with each other. From this point on, the spacer ring 72 presses to the left, and the set of cup springs 81 is compressed. This process continues as long as the compression ring 84 pushes against the outer face 71. Very clearly, the tapered ring 63 contributes to these rotations. The front panel 37 is inserted more deeply into the frame 31, and with it the plug inset element. As the handle 104 is further rotated, when a certain force is exceeded it causes an overlooking of the Hirth serrations 93 and 107, and the handle 104 no longer pulls on the internally threaded device 86.

To loosen the device, the handle 104 is rotated in the opposite direction and the flank 94 of the Hirth serrations 93 and 107 make contact with each other. The front panel 37 begins a tightening motion when the face 82 is opposite the face 83 and when the encircling shoulder 53 is in contact with the face 76. Further rotation causes the jacket 49 to be pulled to the left, and the plug insert is pulled out, together with the catch plate 57. Thus the tapered ring 73 remains on the hub projection 39, so that the entire device does not swing downward, the consequence of which would be that the I a hook attached to one plug-insert element,

a control grip rotatable on the spindle which moves back and forth along the spindle depending on the direction of rotation thereon,

a tapered ring surrounding the spindle and coaxial there-with, possessing an inner chamfer, which can be engaged with the hook, which by rotating the control grip in a tightening direction brings pressure to bear on the hook, and which can be removed from the book by rotating the control grip in the loosening direction once the control grip has been sufficiently loosened,

an internally threaded member rotatable on the spindle and a spring loaded locking joint which couples together the control grip to the internally threaded member and which is capable of limiting the force in one direction when a predetermined plug insertion force is exceeded.

2. A locking device according to Claim 1, in which the control grip and the internally threaded member possess opposed gear-tooth surfaces which serve in the nature of overload release clutch means.

3. A locking device according to claim 2 in which the spring-loading device is a donut-shaped spring cushion made from worked and forged metal wires, the spring cushion being supported and the Hirth-type serrations being subjected to pressure by means of the internally threaded member and the control grip; 

1. A locking device for connecting plug-insert elements comprising a frame which supports these elements having a rotational axis on the frame, a threaded spindle having one end which can be swung around the rotational axis, a hook attached to one plug-insert element, a control grip rotatable on the spindle which moves back and forth along the spindle depending on the direction of rotation thereon, a tapered ring surrounding the spindle and coaxial there-with, possessing an inner chamfer, which can be engaged with the hook, which by rotating the control grip in a tightening direction brings pressure to bear on the hook, and which can be removed from the hook by rotating the control grip in the loosening direction once the control grip has been sufficiently loosened, an internally threaded member rotatable on the spindle and a spring loaded locking joint which couples together the control grip to the internally threaded member and which is capable of limiting the force in one direction whEn a predetermined plug insertion force is exceeded.
 2. A locking device according to Claim 1, in which the control grip and the internally threaded member possess opposed gear-tooth surfaces which serve in the nature of overload release clutch means.
 3. A locking device according to claim 2 in which the spring-loading device is a donut-shaped spring cushion made from worked and forged metal wires, the spring cushion being supported and the Hirth-type serrations being subjected to pressure by means of the internally threaded member and the control grip. 